\tracingonline=2
\tracingcommands=2
\tracingmacros=2
\tracingrestores=2

\catcode`{=1
\catcode`}=2
\newlinechar=`@
\message{@}
\message{~ \meaning aa @}
\message{~ \meaning bb @}
\message{~ \meaning 11 @}
\message{~ \meaning \par @}
\message{~ \meaning\relax @}
\message{~ \meaning \show @}
\message{~ \meaning \undefinedcmd @}
\message{~ \meaning \! @}

\end

